In recent years, reductions in CO2 emissions are being sought with a view to preventing global warming, and hybrid vehicles, idling-reduced vehicles, etc., are being developed in earnest. When connecting control apparatuses and automotive electric motor-generators in such vehicles, wiring length is increased if the control apparatus and the automotive electric motor-generator are separated greatly. Because wiring resistance between the control apparatus and the automotive electric motor-generator is thereby increased, increasing voltage drop, it has been difficult to achieve desired torque characteristics, rotational frequencies, etc. Other problems have been increased weight, and increased cost, etc., due to the increased wiring length.
In view of these conditions, an integrated control apparatus automotive electric motor-generator that includes semiconductor elements has been proposed (see patent Literature 1, for example). This control apparatus has a construction that is constituted by three radiating plates that have differing electric potentials. In order to satisfy cooling efficiency, the semiconductor elements and electrode plates are configured so as to be in a ratio that is greater than or equal to 5.
Patent Literature 1: Japanese Patent Laid-Open No. 2004-208487 (Gazette)